MOre is better but the gun has to fit. Find out what fits you the best. Wilson makes a 10 round double stack gun that is thinner than single stack guns.
PAT
What are you planning on using the weapon for ? I.E. competitive shooting, personal defense, duty. That should weigh heavily on the capacity of the magazine.
Mostly for CCW since I don't compete yet. It will be in the 9x23 round so I can go 10+1 or 19+1.
My Hands are not large but I can handles a glock .45 with 15 rounds in it comfortablly. And weight isn't a concern.
I do cary my Govt Model 1911 .45 all day and it doesn't bother me. Maybe when I get old it will be a cocern but right now and as long as I stay in shape like I am. I don't think 4-5 lbs is too much of a concern.
Well think of this, the more in the mag the thicker the grip. The thicker the grip the harder it is to conceal. As for the weight, I dont mind a heavy gun myself, in fact it may help with the recoil. But another point, with a higher capacity magazine you wont have to worry as much about carriying extra mags.
Contact Dane Burns at http://www.burnscustom.com . He specializes in 9x23 1911's and can probably give you a good opinion on your choices. You can also find Dane on the Tactical Forums.
If you're building for CCW, go single stack. Double stack mags may hold more, but if you have a problem with a mag, you still want another one -- and carrying singles is so much more comfortable (and concealable) than doubles.
(Well, at least it is for me... I'm fairly skinny... and I can put both extra mags in a pocket in a pinch)
Rationale: If it's a problem that can't be taken care of with 22 Black Talons (7+1 plus 2 7s) then it's doubtful another 21 rounds (14+1 plus 2 14s) would make much difference.
And... it's a lot easier to explain 8 hits than 15...
"...I was scared ****less, and I just kept firing until it was empty..."
That's one of the problems I'm coming up against. Do I go with the 10+1 and carry an extra mag or go with the thicker grip 19+1 and carry no mag on my person. Either way I'll have spare mags in the car.
Why? Thinner pistols are generally easier to handle and conceal well. The deminished capacity is not the problem marketers of high capacity magazines would lead you to believe. But that's just one opinion...
Given your criteria, I advise the 10 plus one platform, provided that the pistol is sized around 10 round magazines.
Why? Smaller pistols are generally easier to conceal. Thinner is almost always better, unless you have unusually large hands. Most people don't.
If you are considering a pistol designed to accomodate high capacity magazines, carry high capacity magazines. Why purposefully deminish efficiency?
one other thing to consider is that single stack mags are inherently more reliable than double stacks, be they STI, PO Caspian...etc. ds mags require constant attention to their springs (which is no problem for IPSC) and this is why I'd go with the ss for a CCW (reliability).